The primary research goals of this project are to study the perception of speech sounds for children with articulation disorders. Three aspects of this process are being studied. First, the discrimination of children with articulation errors of /r/ have been compared with normal children on the perception of /r/ in citation form and in running speech. Additionally, these children were examined for non-English sounds (Mandarin) as well. The children with /r/ errors show a deficit in the perception of /r/ about equally for citation form and for running speech. However, on the Mandarin sounds, they perform the same as the normal speaking children. This suggests a deficit in processing specific to the /r/ sound. Second, children have been compared with adults on the perception of Mandarin sounds and tones. Adults perform far better on these tests. Further study of the critical period of perception is being made. Third, perception of sounds in running speech is being examined at all levels. The study on stops show that a loss in perception of segmented speech cannot be due to the stops. Currently we are investigating fricatives and approximants. In summary, research on the development of perception is continuing in three areas. These results may provide information on relationship between speech development and speech perception.